Enhanced Rashba effect in transverse magnetic fields observed on InGaAs/GaAsSb resonant tunneling diodes at temperatures up to T = 180 K

Abstract

A huge Rashba splitting enhanced by an in-plane magnetic field is observed in non-magnetic InGaAs resonant tunneling diodes with GaAsSb barriers. At T = 4 K, the current resonances split by the Rashba effect reveal peak to valley ratios up to 2.5:1 and the energy spacing between the split peaks reaches 30 meV at B = 5 T. The observed peak splitting can be observed at temperatures up to T = 180 K and higher. The Rashba parameters determined on four different samples are between α = 0.38 eVÅ and α = 0.78 eV Å, which are consistent with theoretical values reported for InAs quantum wells under external electric fields.

Mesoscopic spin-orbit effect in the semiconductor nanostructure electrongfactor

“…Most importantly, it is also still not clear what is the relation between g * QW and the Rashba SO coupling, for which different indications exist. 10,20,21 Finally, despite representing the most natural QW extension of the analytical bulk result in Eq. (1), 22 the use of the theory in Ref.…”

InGaAs/GaAsSb based two-dimensional electron gases

“…Similar effects were observed in GaAs/Al x Ga 1Àx As and In x Ga 1Àx As/In x Al 1Àx As 2DEGs. 20 The Rashba parameter can be decomposed into two parts: 35,36 One material dependent part, which can be calculated from the bandgap and the spin-orbit gap, as well as the effective mass and which is constant for a particular material. Alternatively, CuPt-ordered domains in the GaAs 0.51 Sb 0.49 barrier layer could also be responsible for orientation dependent scattering.…”

“…Alternatively, CuPt-ordered domains in the GaAs 0.51 Sb 0.49 barrier layer could also be responsible for orientation dependent scattering. 20 Rashba parameters between 0.38 and 0.78 eVÅ were calculated from the experimental data. RASHBA SPIN SPLITTING Two-dimensional electron systems based on In 0.53 Ga 0.47 As/GaAs 0.51 Sb 0.49 heterostructures show interesting physical properties, despite their relatively low electron mobilities.…”

“…20 The Rashba parameter can be decomposed into two parts: 35,36 One material dependent part, which can be calculated from the bandgap and the spin-orbit gap, as well as the effective mass and which is constant for a particular material. 20 Rashba sin-orbit coupling of the same order of magnitude (0.64-0.74 eVÅ ) was reported for highly strained In x Ga 1Àx As/ InP 2DEGs, which were patterned into quantum wires. As the second contribution, this term must be multiplied with the electric field at the interface.…”

“…Depending on the actual application, many different material combinations are applied. 18 Studies on In 0.53 Ga 0.47 As/GaAs 0.51 Sb 0.49 resonant tunneling diodes in magnetic fields revealed strong nonparabolicity and Rashba effects, 19,20 due to the low bandgaps and type-II nature of the band alignment. Recently, In 0.53 Ga 0.47 As/GaAs 0.51 Sb 0.49 heterostructures were demonstrated to be a viable way to fabricate midinfrared and THz quantum cascade lasers (QCLs).…”